A bad storm can keep you snowed in and leave grocery shelves empty even after the streets have been cleared. And heavy snow combined with high winds can mean extended power outages.
If you're one of the millions of Americans who will be impacted by the winter wallop headed to the East Coast this weekend, you need to get ready. Here's some practical advice from the Federal Emergency Management Agency on how to prepare for storms:
Medical
Refill your prescriptions before they run out. Always have enough on hand to cover for extended power failures, when stores and pharmacies may be closed and unable to get fresh supplies. Have a medical kit in the house with bandages, antibiotic ointment, aspirin, ibuprofen or other analgesics, antihistamines in case of an allergy attack or an insect bite, and alcohol to clean wounds. Know what your prescriptions are in case the worst happens and your home is destroyed or you cannot get back home for a long time.
Always have at least three days' worth of non-perishable food on hand. It won't do you any good if it has to be refrigerated and the power goes out for a week, so make sure to have crackers, dry cereal, pop-open cans of food, shelf-stable juice or milk, soup, etc. on hand. Keep a non-electric can opener in a drawer. Don't forget basic needs for pets and small children.
Flashlights
Have plenty and make sure the batteries are fresh. A hand-cranked flashlight will work forever, even after batteries run out. That comes in handy in worst-case scenarios: People were without power for weeks and even months after Superstorm Sandy hit the Northeast in 2012 and after Hurricane Katrina in 2005.
Power
Be prepared to go without electricity for several days, at least. If you have electric-only heat, how will you keep your home warm? Many gas-heated homes need electricity, too. Many gas furnaces have electric pilot lights, and HVAC systems need electricity to push air. Using a barbecue or even a gas stove for heat can prove deadly — both create carbon monoxide fumes. The single biggest cause of death during power failures in the U.S. is carbon monoxide poisoning. Most cases are of people who didn't realize that bringing an outdoor barbecue inside is a deadly mistake. Even keeping it just outside a door can allow deadly fumes to come inside.
Communication
Wireless handsets won't work in a power failure. Old-fashioned landlines will, but if you've gone digital — and many people have — cell phones won't. Cell towers may go down in a widespread failure, rendering your smartphone useless. Have a backup battery and at least one cellphone booster charger on hand. Hand-cranked or battery-powered radios will allow you to tune to emergency information broadcasts. Make sure you have fresh batteries.
Hygiene
Have plenty of hand sanitizer and antiseptic wipes on hand. A few drops of bleach can disinfect water if bacterial contamination is a worry, although bleach won't remove chemical contaminants. Have paper towels and plastic garbage bags to get you through an extended power failure.
If all else fails, a wood fire will provide warmth. If you have a fireplace, make sure the chimney is in shape, inspected and ready to go. Have dry, cured wood on hand. Don't try to use a fire to heat your house if you don't have a fireplace, however. Burning newspapers or any other paper products can set a chimney on fire. Anything combustible needs to be burned outdoors, away from structures.
Fire extinguisher
Always have several fire extinguishers in your home. Make sure they're not out of date. Old ones may not work right.
Winterize outside
Make sure rain gutters are clear and the roof is well-insulated. Ice dams can form during winter storms if the gutters aren't clean and straight, and they can flood a home at the worst possible time.
Big power failures can disrupt your water supply if pumps aren't running, and flooding can foul the water supply. Every household should have plenty of clean drinking water on hand at all times. The rule of thumb is three-quarters of a gallon per person per day — that's three quarts. It also doesn't hurt to have extra clean water for washing and food preparation. And a gallon container of water will flush your toilet if the water is shut off.
This article fist appeared on NBCNews.com.